This guide covers a quick troubleshooting step to help fix connection issues between the Handheld and Terminal.
You should first start with restarting both devices and then testing if they still won't connect to each other after both devices have been restarted.
You should then check and confirm that both devices are on the same network as not being on the same network could be the cause of the issue.
If none of these help with the issue, please make your way to the main Terminal screen and find the app named "POS Steward", this app will most likely be in the folder named "Tools" on the main screen.
Once you are in the app, click on "Device Health Check" and go through all the steps displayed, if there are any issues please contact us immediately using this link.
Another reason as to why the device is not communicating to the Terminal is that it has not been bound to the Terminal.
Here is a link to a article which will guide you through the steps to bind the Handheld to the Terminal. - How do I bind my Handheld to my Terminal?
You can also try changing the IP Setting of the network on your Handheld Device.
To do this, first go onto the Handheld's main screen and click on the gear icon.
Next, click on "Network & Internet".
Once you can see your Wi-Fi network you are connected to, click on it.
Then click on the gear icon next to the network.
You will then want to click on "Advanced" at the bottom of the screen and please make a note of the IP address and Gateway.
Once you have made a note of these two values, please click on the Pencil Icon.
You will then need to click on "Advanced Options" and the rest of the menu will drop down.
Once the menu has dropped down, click on "IP Settings" and change it from DHCP to Static. 
DHCP is the default IP Setting, Once you have changed the IP Setting to static, fill in the IP address and Gateway with the values you noted down before. Below Gateway, it will display two DNS boxes, please enter 8.8.8.8 in the first box and in the second one, please enter 8.8.4.4.
Once you have done this, press save and restart both devices and try to see if it will connect. If it does not connect then go back through the steps and change the IP Setting to DHCP and save.
Having the IP Setting on Static is a temporary fix.
If you have any questions or require further assistance, please feel free to reach out here.